A wireless communications system and, more particularly, to a dynamic uplink power control method and device in a wireless communications system are disclosed. A method for dynamically controlling an uplink transmission power at a base station is provided, the method includes the steps of receiving an uplink signal from a user equipment being served by the base station, deciding whether or not an uplink transmission to the base station from the user equipment causes an interference with another base station, and transmitting a transmission power control (TPC) command muting the uplink transmission to the user equipment.